Lead(II) carbonate basic

Description

Lead carbonate—white lead—is found as the mineral cerussite, which is mined and processed to produce lead and lead compounds. White lead has also been used as a pigment since antiquity; however, it has been phased out in many countries because of its toxicity. Although other white pigments exist (zinc oxide, titanium dioxide), many artists continue to use flake white, which is made with lead carbonate, because of its superior properties, such as fast drying and better durability.

Chemical properties

dense white powder

Chemical properties

Basic lead carbonate forms white hexagonal crystals; it decomposes when heated to 400 °C. It is insoluble in water and alcohol, slightly soluble in carbonated water, and soluble in nitric acid.

The Uses of Lead(II) carbonate basic

Lead(II) carbonate basic can be used as pigment in oil paints and water colors; in cements; for making putty and lead carbonate paper; in the processing of parchment.

The Uses of Lead(II) carbonate basic

Lead(II) carbonate is used in ceramic glaze and exterior paint.

Definition

Acid-soluble, heavy, white powder or crystalline substance, insoluble in water and alco- hol.

Preparation

Many commercial processes have been developed for manufacturing basic lead carbonate. These include: Thomson-Stewart process, Carter process, and Dutch process. The method of preparation involves treating lead with acetic acid vapors in the presence of carbon dioxide at 60°C. In the Thomson-Stewart process, finely divided lead monoxide or lead metal is mixed with water to give aqueous slurry, which is then mixed with acetic acid in the presence of air and carbon dioxide. All these processes are slow, taking weeks to obtain products of desired composition.
Basic lead carbonate also is precipitated by dissolving lead monoxide in lead(II) acetate solution, and treating the solution with carbon dioxide. It also is produced by electrolysis of sodium nitrate or sodium acetate using lead anode and then precipitating out the product by adding sodium carbonate.
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Production Methods

Basic Lead Carbonate is produced by several methods, in which soluble lead acetate is treated with carbon dioxide. For example, in the Thompson-Stewart process, an aqueous slurry of finely divided lead metal or monoxide, or a mixture of both, is treated with acetic acid in the presence of air and carbon dioxide. High quality, very fine particle-size basic lead carbonate is produced, ranging in carbonate content from 62 to 65% (vs 68.9% PbCO3, theoretical).

Flammability and Explosibility

Non flammable